The Clinical/Statistical Core will provide the research projects with appropriate human clinical specimens and data from studies of vaccination or infection for influenza, pneumococcus, and varicella zoster virus. The Clinical/Statistical Core has three units that will support the research projects: the Hope Clinic Unit located at Emory U.; the Denver Clinic Unit located at the U of Colorado; and the Statistical Unit located at Emory U. The specific aims of the Clinical/Statistical Core are: Specific aim 1) To provide clinical study expertise and capacity to ensure the success of the U19 scientific agenda. Specific aim 2) To provide statistical and data management expertise that ensures the success of the U19 scientific agenda. Specific aim 3) To perform clinical studies with inactivated trivalent influenza vaccine (TIV) that will provide the clinical specimens and data necessary to accomplish the scientific aims of the research projects. Specific aim 4) To perform clinical studies with 23-valent pneumococcal polysaccharide vaccine (PPV23) and in subjects with pneumococcal infections that will provide the clinical specimens and data necessary to accomplish the scientific aims of the projects. Specific aim 5) To perform clinical studies with zoster vaccine (ZV) and with herpes zoster (HZ) patients that will provide the clinical specimens and data necessary to accomplish the scientific aims of projects 1 and 2.